Apparatus for making annular parts

ABSTRACT

An apparatus for punching annular parts from a sheet of stock material, such as a continuous ribbon or tape of plastic material. The apparatus comprises means for feeding the ribbon or tape of stock material between two plate members, clamping a portion of the ribbon or tape between the plate members, and, by means of a pair, or a plurality of pairs, of opposed punch members adapted to be reciprocated in timed relationship to firstly punch from the stock material a slug for forming the center aperture of the annular part, and secondly punch from the stock material the annular part itself. The slug punched from the stock material and the annular part are separated by appropriate aspirator means.

United States Patent 1191 Smith et al.

1111 3,822,622 1451 July 9,1974

[ APPARATUS FOR MAKING ANNULAR PARTS [75] Inventors: Joseph E. Smith,Birmingham;

Raymond P. DeSantis, Royal Oak;

Georges D. Detroyer, Grosse Ile, all of Mich.

[73] Assignee: Wolverine-Pentronix, Inc., Lincoln Park, Mich.

[22] Filed: Aug. 7, 1972 21 App]. No: 278,532

[52] US. Cl 83/100, 83/214, 83/621, 83/623 [51] Int. Cl B26f l/02 Fieldof Search 83/621, 623, 100, 380, 83/214; 10/72 R, 85

[56] References Cited UNITED STATES PATENTS 2,313,525 3/1943 Edelman83/621 X 3,568,554 3/1971 Wieche 83/621 X 3,610,082 10/1971 Riggi et a183/623 X 3,640,167 2/1972 Axtmann 83/623 X FOREIGN PATENTS ORAPPLICATIONS 1,050,322 12/1966 Great Britain 1. 83/621 France 1. 83/621France 83/621 Primary Etaminer-J. M. Meister Attorney, Agent, orFirm-Hauke. Gifford, Patzilidis A: Dumont 5 7] ABSTRACT An apparatus forpunching annular parts from a sheet ofstock material, such as acontinuous ribbon or tape of plastic material. The apparatus comprisesmeans for feeding the ribbon or tape of stock material between two platemembers, clamping a portion of the ribbon or tape between the platemembers, and, by means of a pair, or a plurality of pairs, of opposedpunch members adapted to be'reciprocated in timed relationship tofirstly punch from the stock material a slug for forming the centeraperture of the annular part, and

secondly punch from the stock material the annular part itself. The slugpunched from the stock material and the annular part are separated byappropriate aspirator means.

'15 Claims, 8 Drawing Figures PATENTEU IL I 3.822.622

sum 1 BF 3 FIG! BACKGROUND OF THE INVENTION Very small annular partssuch as, for example, magnetic cores are conventionally made of powdermaterial, such as ferrites and the like, which is compacted in anappropriately shaped die cavity, under high pressure by way of a punchadapted to compact the powder material against an anvil closing the endof the die cavity, or between two oppositely advancing punches disposedin the die cavity. A core rod member is disposed in the die cavity forforming in the center of the compacted mass of powder material anaperture, or hole, such that the finished article, or green core, is inthe form of an annulus, or toroid.

It has been a general trend in many industries, and more particularly inthe electronic and computer industry in which the majority of magneticcores are used, to miniaturize components, and this has led to manydifficulties in forming tiny parts of the order of a few thousandths ofan inch in overall size with precision, constant density, and accuratedimensions. The manufacture of magnetic cores requires very closedimensional and density tolerances so as to achieve consistency'in thephysical and electromagnetic characteristics of the sintered cores. Asthe dimensions of magnetic cores are decreased with a view toward suchminiaturization of the equipment in which they are used, the result isthat a great number of cores may be used within a small frame area and agreat number of frames may be packaged within a small volume, which areall desirable achievements not only with a view toward miniaturizationbut also with a view toward obtaining magnetic cores which can beswitched from a magnetic state to another magnetic state in a very shortperiod of time and with a very small control current. However,difficulties are readily encountered in compacting from powder materialsuch minute parts, seemingly not larger to the naked eye than aspeck ofdust, with the accuracy required. For that reason, it has been foundadvantageous to make magnetic cores of very small dimensions, such as 12mils, 300 microns, or less, in diameter by means other than compactingpowder ferrites and like magnetic materials.-

One of the means contemplated for obtaining miniature magnetic coresconsists in making a thin sheet of calendered plastic binder containingthe appropriate metallic oxides or ferrites in very. fine particlesuniformly dispersed in the binder. The stock material from which themagnetic cores are eventually made therefore takes the form of anelongated pliable plastic sheet or film. Preferably the sheet is slittedlengthwise to obtain several continuous ribbons or tapes of apredetermined width, and a few thousandths of an inch in thickness,which may conveniently be spooled, and from which annular parts, formingthe green magnetic cores, may be punched out as the stock material isunwound from its spool. The tiny annular parts, or toroids, punched fromthe ribbon or tape of stock material are subsequently heated at arelatively high temperature so as to evaporate, or burn out, the plasticbinder and sintered at yet a higher temperature to form magnetic coressuitable for stringing in an appropriate array in a frame, as isconventionally done. The thickness of the stock material determines thefinal height of the magnetic cores after sintering, taking in consider-'ation the shrinkage factor during sintering. The composition of theplastic resin binder must be properly selected so as to permitthesintering of the cores without the formation of deleterious ash orresidue materials in any appreciable amount having an adverse effectupon the final electromagnetic characteristics of the magnetic cores.

The tooling used for punching the green" cores, or unsintered cores,from the tape of stock material is a very high precision tooling of verysmall dimensions and close tolerancesfor making such parts which.although hardly discernible with the naked eye. require extremeconsistency of dimensions: from one part to another, while permittingthe high production rates compatible with an economically viableoperation. Al though a conventional progressive die is generally capableof punching annular parts, a progressive die for making parts as smallas green magnetic cores requires high precision not only in thedimensions of the separate punch and die elements for first forming thecentral aperture in the cores and secondly punching the core from thestock material at a position of the stock material separate from that atwhich the central aperture is punched out, but, more importantly yet, apro gressive die requires very complex feeding and indexing means foreffecting the progressive displacement of the stock material through thedie and for accurately indexing the stock material sequentially at atleast two separate punching stations for obtaining a single fin ishedpart. There result considerable difficulties in forming parts with thehigh dimensional precision and with the high degree of concentricityrequired for a finished product such as green magnetic cores. Suchinconveniences, disadvantages and difficulties are overcome by theapparatus of the present invention which permits to punch the centralaperture and the complete annular part at a single punching positionduring a single stoppage of the stock material progression through thepunch and die assembly and by means of concentric punch and die members.In this manner, the required degree of accuracy in dimensions and inconcentricity is obtained, which cannot be obtained by way of the priorart punch and die apparatus.

SUMMARY OF THE INVENTION The present invention has therefore for itsprincipal object to make, at high production rates, annular parts ofvery small dimensions of the order of a few thousandths of an inch inheight and width, punched from a sheet of stock material such as, forexample, a ribbon or tape of pliable plastic material consisting of auniform dispersion of solid particles in a binder, by means of arelatively simple apparatus consisting of at least a pair of opposed andconcentric punch and die members for forming a completepart from thetape of stock material in a single operation, and to provide simplemeans for intermittently feeding the tape of stock material betweenopposed pairs of punches. The appara-- tus of the invention is in amodular [form which permits interchangeability with the tooling normallyused on a powder material compacting press for forming parts fromcompacted powder material which, as will be obvious to those skilled inthe art, presents a commercial and technological advantage of greatvalue resulting from an efiicient use of already existing machinery.However, as will also be obvious to those skilled in the art, thepresent invention may be incorporated in any other machine capable ofproviding appropriate driving means for the stock material feedingmechanism and for the punch and die members actuating mechanism.

The many objects and advantages of the present invention will becomeapparent when the following description of the best mode contemplatedfor practicing the invention is read in conjunction with theaccompanying drawing.

BRIEF DESCRIPTION OF THE DRAWING FIG. 1 is a longitudinal sectional viewof an example of apparatus according to the present invention;

FIG. 2 is a top plan view of a portion of the apparatus of FIG. 1, asgenerally seen from line 22 of FIG. 1, and omitting some elements forthe sake of clarity;

FIG. 3 is a sectional view from line 3-3 of FIG. 2;

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT An apparatus accordingto the present invention, designated by numeral at FIGS. 1, 2 and 4,takes the form of a multiple punch and die unit adapted for mounting onthe table of a machine, such table being indicated at 12 in FIGS. 2 and4. The machine may be, for example, any one of the Multipak (RegisteredTrademark) powder compacting presses made by the Pentronix Division ofWolverinoPcntronix, Inc. of Lincoln Park, Mich., or any one ofthepresses disclosed in US. Letters Pat. Nos. 3,328,840, 3,328,842,3,344,213, 3,415,142, 3,561,054, 3,561,056, 3,574,892 and 3,645,658, allassigned to the assignee of the present application. The apparatus ofthe present invention may also be mounted on the table of anyappropriate machine provided with either cam actuated or hydraulicactuated upper and lower punch member driving means. For illustrativepurpose only, the invention will be described as being adapted formounting on the table ofa Multipak powder compacting press, or any oneof the presses disclosed in the above mentioned patents, instead of thepowder compacting punch and die module, or tool set, normally mountedthereon and interchangeable with such powder compacting punch and diemodule.

The apparatus 10 comprises a base plate 14 mounted over an appropriateaperture in the table 12 and fastened thereon by any convenient means,such as bolts 16. The base plate 14 has on its upper surface a recess 18in which is mounted a plate member 20, also by means of any convenientfastening means such as screws and the like, not shown. Three columnmembers 22, two of which only can be seen in FIG. 1 are each mountedthrough an appropriate bore 24 axed at right angle to the upper andlower surfaces of the base plate 14. The column members 22 are fastenedin the bores 24 by any convenient means, such as being press-fittedtherein, cemented, or held by set screws or the like, not shown. Thecolumn members 22 project a certain distance above and below the baseplate 14.

Mounted below the base plate 14 there is a punch holder member 26provided with an enlarged diameter portion 28 having three axial bores30, each aligned with and defining a linear bearing for one of thecolumn members 22, such that the punch holder member 26 is reciprocablerelatively to and below the base plate 14. The punch holder member 26 isprovided at its lower end with an actuating stem 32 fastened to areciprocating means depending from the driving mechanism of the machine(not shown) on which the apparatus of the invention is mounted. The endof the punch holder member 26 disposed toward the base plate 14 has apunch mounting block 34 fastened thereto which is adapted to accept aplurality of lower punch members 36, preferably made of carbide,disposed in two parallel rows, each row comprising several punch memberssuch as, for example, 10, 12, 14 or more punch members in each row,according to the width of the stock material from which finishedarticles are to be punched and according to the size of the finishedarticles. Such rows of punch members 36 extend transversely at a rightangle to the plane of the sheet of paper on which FIG. 1 is drawn.Preferably the punch members in alternately one row and the other arestaggered so as to reduce to a minimum the amount of scrap materialremaining in the stock material after the finished articles are punchedfrom the stock material.

The punch members 36 are mounted in appropriate bores 38 in the punchmounting block 34, the coincident axes of each bore 38 and associatedpunch member 36 being parallel to the axes of the column members 22. Thepunch members 36 are fastened in the bores 38 of the punch mountingblock 34 by an appropriate means such as being press-fitted therein orby being cemented therein. The punch members 36 are hollow, as bestshown at FIGS. 58, and are thus provided with an internal bore 40 whichis placed in communication with a manifold or collector 42, formed inthe punch holder member 26. The manifold or collector 42 is provided atits lower end with an outlet passageway 44 and an appropriate fitting,not shown, to which is connected a flexible line 46 in turn connected toan aspirator means, not shown, such that any particle falling in themanifold or collector 32 may be evacuated.

Part of the base plate 14 is cut-out below the plate member 20 and theplate member 20 has a plurality of bores 48 each slidably acceptingtherethrough one of the punch members 36 which have normally their upperend constantly engaged in the bores 48.

Above the base plate 14, there is an upper plate 50, as shown at FIG. 1,provided with appropriate through bores 52 each adapted to slidablyaccept therethrough the upper projecting portion of a column member 22.The upper plate 50 has, on its lower face, a recess 54 in which ismounted a plate member 56, preferably made of a very hard material suchas a carbide or the like and fastened therein by any convenient means,and which is provided with two parallel rows of staggered die apertures58, each of which is axially aligned with one of the bores 48, andconsequently one of the lower punch members 36. In the example ofconfiguration illustrated, the plate member 56 has a ridge 60 extendingtransversely between the two parallel rows of die apertures 58, althoughthe ridge may be omitted. The top surface of the upper plate 50 isformed as a V-shaped recess 62, the apex of which is directed towardsthe rows of die apertures 58 in the plate member 56. A plurality oftubes 64, each corresponding to one of the die apertures 58 and havingits end proximate such die aperture, are clamped by means of clampingblocks 66 on both angled surfaces of the U-shaped recess 62 on the upperplate 50, the other end of each tube 64 being connected by means of anappropriate flexible line to the inlet of an aspirator 68 which may beof the type disclosed in copending application Ser. No. 173,452, now US.Pat. No. 3,768,952, such that each individual article extracted fromeach die aperture 58 is finally collected in an individual receptacle70, each individual receptacle 70 corresponding to one of the dieapertures 58 so as to segregate the production of each die aperture fromthe production of every other die aperture.

A platen 72 is disposed above the upper plate 50 and is provided withappropriate bores 74, each adapted to slidably accept one column member22 therethrough. It is obvious that each bore 74 in the platen 72, aseach bore 52 in the upper plate 50, and each bore 30 in the lower punchholder member 26, may be provided, and is generally provided, with anappropriate linear bearing or bushing for the purpose of achievingproper alignment of the elements and low wear and friction duringrelative reciprocation of the elements when the apparatus is inoperation. The platen 72 is further provided, on its lower face, with anupper punch mounting block 76 fastened thereon by any convenient meanssuch as pins and bolts, and the punch mounting block 76 is in turnprovided with a plurality of bores 78, disposed in parallel staggeredrows, each one adapted to accept an upper punch 80 for rigid mountingthereon by cementing, press-fitting, or any other convenient means. Eachupper punch 80 is conveniently made of a cylindrical rod of hard metalor alloy, such as a carbide as tungsten carbide, press-fitted into atubular cylindrical member 82, for example made of steel, which is inturn press-fitted, cemented or otherwise fastened in the bore 78 of thepunch holder block 76.

The bottom end portion, as seen in FIG. 1, of each bore 74 in the platen72 is countersunk, as shown at 84, and thus forms a recessed annularabutment 86 engaging the upper end of a compression coil spring 88, eachcoil spring 88 being disposed surrounding one of the column members 22between the upper annular abutment 86 in the platen 72 and a similarannular abutment 90 formed in the upper face of the upper plate 50 aboutthe bore 52. In this manner, when the platen 72 is displaced downwardly,the resultant compression of the coil springs 88 exert a downwardlydirected bias that urges the upper plate 50 towards the base plate 14.Spring means, such as Belleville springs 92, are disposed around each ofthe column members22 in a pocket 94 formed in the upper face of the baseplate 14 to urge the upper plate 50 away from the base plate 14. Thestrength of the Belleville springs 92 is sufficient to normally supportthe combined weights of the plate member 50 and the platen 72, and thecoil springs 88 in turn supports the platen 72 away from the upper plate50 in the position represented at FIG. 1. Under those conditions, theplate members and 56 are apart from each other, thus permitting a sheetof stock material 96, preferably in the form of a ribbon or tape of suchstock material, to be fed between the plate members 20 and 56 by meansof two pairs of opposed feed pinch rolls 98100 and 102-104, mountedrespectively on shafts 106-108 and 110-112, ahead and beyond the upperplate 50. After the ribbon or tape of stock material 96 has beenadvanced between the plate members 20 and 56 by the feed rolls 98100 and102-104 and stopped, an upper ram member 114, forming one of the driveoutputs of the machine on which the apparatus of the invention ismounted, is reciprocated downwardly such as to engage the upper face ofthe platen 72 and drive the platen downwardly. The downward motion ofthe platen 72 compresses the springs 88, thus in turn displacingdownwardly the upper plate 50 such that a portion of the stock material96 is finnly clamped between the plate members 56 and 20. The Bellevillesprings 92 are designed such as to be weak enough to compresssufficiently for allowing a slight downward motion of the upper plate 50which effects the clamping of the stock material 96 between the platemembers 20 and 56. Further downward reciprocation of the ram member 114causes further downward motion of the platen 72, while compressing thecoil springs 88, and the upper punch members are reciprocated throughthe die apertures 58 in the plate member 56, sequentially withreciprocation of the lower punch members 36 mounted in the lower punchholder 26 by means of the drive output of the machine connected to thepunch holder actuating stem 32. The diverse punching operationsnecessary to form an annular part are thus effected sequentially, aswill be explained hereinafter in further detail, at a single position ofthe stock material. After the punching operations have been effected,the upper ram member 114 is reciprocated upwardly to the position shownat FIG. 1,

such that the stock material 96 is; no longer clamped between the platemembers 56 and 20 and is further advanced therebetween by means of thefeed pinch rolls 98-100 and 102-104 to a subsequent position presentinga fresh area of the stock material to the action of the punch and diemembers. The: clamping step and punching operations are then repeated.

FIGS. 5-8 graphically show the successive steps involved in punching afinished part from the sheet of stock material 96. Duringfeed of thesheet of stock material 96 between the plate members 56 and 20, theplate members are separated at least by a distance sufficient to permitadvance of the stock material therebetween, as shown at FIG. 5. The endof each lower punch member 36 is substantially flush with, or slightlylower than, the upper end of the aperture 48 in the plate member 20.After the sheet of stock material 96 is clamped in position between thetwo plate members 56 and 20, the lower punch members 36 are positionedin engagement with the lower surface of the stock material and the upperpunch members 80 are advanced through the die apertures 58 in the platemember 56 to the position schematically shown at FIG. 6, causing the endof each punch member 80 to project within the end of the bore 40 of eachlower punch member 36, thus piercing the sheet of stock material 96 as aresult of cutting out a slug or disc, shown at 116 falling by gravitythrough the bore 40 in the lower punch member 36, with the formation ofa hole or aperture 118 in the sheet of stock material. The slugs ordiscs 116 of stock material, which are scrap, fall in the manifold 42(FIG. 1) formed in the lower punch holder 26, and are evacuated byaspiration through the passageway 44 and flexible tubing or line 46.

The upper punch members 80 are subsequently retracted, while the lowerpunch members 36 are simultaneously, or subsequently, retracted slightlyand then advanced upwardly into the die apertures 58 in the plate member56 to pierce a larger hole 120 (FIG. 7) in the sheet of stock material96, resulting in the formation of a toroidal or annular-shaped article122. The annular article 122 is ejected from the die aperture 58 in theplate member 56 as a result of the lower punch 36 being furtherdisplaced upwardly to a position (FIG. 8) causing its end to be at leastflush with the upper end of the die aperture 58, or preferably slightlyprojecting therefrom, and the annular article 122 is aspirated throughthe tube 64. Preferably, to insure that the annular article willseparate from the end of the punch 36 to which it may stick, the punch36 is first reciprocated such that its end projects slightly above thedie aperture 58, then retracted within the die aperture to strip theannular article from the punch end, and then reciprocated again to aposition whereby its end projects slightly above the die aperture. Inthe configuration illustrated, the ridge 60 on the upper surface of theplate member, or die plate, 56 acts as a dam preventing each individualaspirator tube 64 from aspirating any annular article other than the onebeing ejected from the particular die aperture serviced by thataspirator tube. Alternatively, the end of the aspirator tube 64 isshaped as tosurround the upper punch member 80, such that in eitherconfiguration the diverse finished articles are appropriately segregatedin the containers 70 (FIG. 1), each container collecting only thefinished articles originating from a particular die aperture.

In order to use calendering and slitting machines already on the market,for example for making photographic films, it is convenient to adopt astandard width for the ribbon or tape of stock material 96, with theresult that the ribbon or tape of stock material is conveniently ofawidth such as for example 16 mm, 35 mm, or a like convenient dimension.The stock material, as previously explained, consists ofa plastic filmof an appropriate thickness, for example 6 to 10 mils, or 150 to 240microns, with, for example if it is desired to manufacture magneticcores, fine particles of magnetic metallic oxides or ferrites uniformlydispersed throughout the mass of the film. Annular articles, such asgreen" magnetic cores, may be formed by means of the apparatus of theinvention with an outer diameter in the range of 20-9 mils, or 500-225microns, or less with a center aperture or hole in the range of 12-4mils, or 300-100 microns, or less. Utilizing an apparatus having tworows of 14 die apertures and punch pairs, for example a total of 28green' cores are punched in the course of a single stroke of theapparatus. The apparatus may be mounted on a machine that drives it, forexample, at 700 strokes or more per minute, with the result that theproduction rate obtained amounts to about 1,200,000 green cores perhour. Because the production originating from each die aperture issegregated from the production originating from every other dieaperture, a malfunction associated with one or more die apertures, dueto punch breakage or uneven wear of the punches and die walls, may beignored, as the remaining good cores are separatedfrom the bad cores,until it is convenient to stop the machine for replacing the punch anddie assembly of the apparatus of the invention by a new one, or foreffecting any maintenance work that may be required.

The intermittent feed mechanism for the tape or ribbon of stock material96 will now be described in detail, with reference to FIG. 1 and moreparticularly to FIGS. 2-4. The tape of stock material 96 isnormallyspooled on a reel, not shown, conveniently mounted on a reel horse orother convenient means permitting unimpeded unwinding of the tape ofstock material 96 from the reel. The leading edge of the tape or ribbonof stock material 96 is manually engaged between the opposed pinch rolls98 and 100. The roll 98 is mounted above the base plate 14 and is keyedor otherwise fastened to the shaft 106 which is intermittently driven,as will be explained hereinafter. The roll 100, disposed below the levelof the upper face of the base plate 14, in a cut-out portion thereof, isconstantly urged by way of a spring bias towards the driven feed roll 98so as to apply the upper face of the tape of stock material 96 againstthe peripheral surface of the feed roll 98. Sub sequent advance of thetape of stock material through the apparatus is, prior to and after theleading edge of the tape reaches the feed pinch rolls 102-104, effectedautomatically during the operation of the apparatus, by means of boththe pairs of feed pinch rolls 98.-100 and 102-104, in appropriate timedrelationship with the reciprocation of the upper and lower punches and36 during the period of time when the plate members 20 and 56 are urgedaway from each other as a result of the upper plate 50 being supportedby the Belleville spring 92. The structural arrangement of the pairs ofpinch rolls 98-100 and 102-104 is the same, the only difference beingthat the periphery of the feed roll 98 is smooth so as not to mar thesurface of the stock material 96, while the periphery of the feed roll102, which engages the tape of perforated scrap material proceeding fromthe punching apparatus of the invention, is provided with a knurled orotherwise highly frictional surface 124 for providing a better grip onthe surface of the tape of perforated scrap material to insure positivedrive thereof.

If so desired, the distance between the axes of the rolls 98 and may bepreset at a constant value such as to create a well defined clearancebetween the peripheral surfaces of the rolls providing a precisethickness sizing means for the tape 96.

As shown in particular details at FIG. 3, relative to the pair ofdownstream pinch rolls 102-104, each idler roll 100 or 104 is springloaded towards its respective feed roll 98 or 102 by way of a pair ofplungers 126, each disposed in a vertical bore 127 in the base plate 14and biased by a compressed coil spring 128 such as to radially engagethe ends of the shaft 108 or 112 on which is mounted the idler roll 100or 104. It is obvious that the idler roller 100 or 104 may be coupled bygear, or other, means to'its respective feed roll 98 or 102. The shaft108 or 112 is supported at both ends in a somewhat upwardly elongatedbearing surface 130 formed in the pinch roll support brackets 132. Theidler rolls 100 and 104 are preferably mounted on their respectivesupport shafts 108 and 112 so as to be freely rotating therearound. Thefeed roll 98 or 100 being rigidly maintained along a constant horizontalaxis of rotation by way of the shaft 106 or being journaled in thesupport brackets 132 by means of appropriate bearings such as needlebearings 134, the tape of stock material 96 is thus urged in drivingengagement with the peripheral surface of the intermittently driven feedroll 98 or 102, and the arrangement of the feed pinch roll pairs thusfurther permits to accommodate various thicknesses of tape stockmaterial.

The feed roll drive shaft 106 or 110 projects from the rear supportflange 132 and is journaled in the bearing 136 of an additional supportbracket 138. A commercially available one-way clutch mechanism 140 ismounted on the end of the shaft 106 or 110 projecting beyond the supportbracket 138 and one end of a crank arm 142 is fastened to the peripheryof the one-way clutch 140, as shown at FIGS. 2 and 4. The other end ofthe crank arm 142 is pivotally connected by means of a pivot pin 144 toan end of a connecting arm 146, such that when the connecting arm 146 isoscillated, both crank arms 142 are swung in unison. A verticallydisposed roller 148 is mounted below the connecting arm I46 and isengaged in ahorizontal slot 150 formed by the bifurcated ends 152 of anarm 154 radially projecting from an angularly, or circularly,reciprocating drive member 156 mounted on the table 12. The radiallyreciprocating member 156 is part of the machine on the table 12 of whichthe apparatus of the invention is mounted and, when such machine isoperated as a powder material compacting press, diverse elements such asthe powder material dispenser, the compacting anvil, and the finishedpart ejecting or pick-up mechanism are normally mounted on the end ofthe arm 154, as explained in detail in the aforementioned patents.

It is evident from the preceding description that when the angularlyreciprocating or oscillating member 156 is angularly reciprocated of onearcuate stroke around a vertical axis in timed relationship with theoperation of the other drive means for the punch and die apparatus ofthe invention, such angular reciprocating being timed such as to beeffected at the appropriate moment when the plate members 56 and 20 areno' longer clamping the tape of stock material 96 therebetween, theconnecting arm 146 driven by the arcuately reciprocating arm 154 iscaused to oscillate horizontally. The two one-way clutches 140, mountedrespectively on the end of the shaft 106 and on the end of the shaft110, are arranged such that when the connecting arm 146 is displacedleftwardly, FIGS. 2 and 4, and the,

upper ends of each the two crank arms 142 pivotally attached to the endsof the connecting arm 146 is also caused to be displaced leftwardly, theone-way clutches 140 drive the shafts I06 and 110, and consequently thefeed rolls 98 and 102, counterclockwise of a predetermined are, thusfeeding the tape of stock material 96 of a predetermined distancerightwardly, as seen in FIGS. 1, 2 and 4, such that a fresh portion ofthe tape of stock material 96 is caused to index with the punch and dieassembly forming part of the apparatus of the present invention so as topunch further annular articles during subsequent clamping of that freshportion of the tape of stock material 96 between the plate members 56and 20. The return stroke of the arm 154 may be effected at anyappropriate time during clamping of the tape of stock material betweenthe plate members 56 and 20, and during such return stroke causing arightward displacement of the connecting arm 136, the one-way clutches140 are automatically disengaged, or free wheeling, such that no torqueis applied to the feed roll drive shafts 106 and 110.

The sequential and timed advance, or linear translation, of the tape ofstock material 96 between the plate members 56 and 20 is thus effectedby a small increment at a time, of a distance each time which issufficient only to clear the perforated portion of the tape of stockmaterial from between the punch and die mecha nism. Such increment maybe of the order of l/60,000 of an inch, or 1.5 mm, or less.

The increment of tape advance may be set such that the two parallel rowsof holes 120 punched in the tape 96 during one punching cycle of theapparatus are con tiguous to each other or alternatively, set such thatthe rows are separated by a distance that permits one row of holespunched in the subsequent punching cycle to be situated in the tapematerial remaining between the two parallel rows punched at the firstpunching cycle. The advance increment can be set in one of severalalternative manners. For example, the arms 142 (F IG. 3) may be madesuch as to have an adjustable length or, alternatively, the roller 148(FIGS. 2 and 4) mounted below the connecting arm 146 may be mountedtherebelow, adjustable along the longitudinal axis of the connecting arm146 such that the vertical axis of the roller 148 may be disposed somedistance away from the middle of the connecting arm 146. Alternatively,and preferably, the arm 154 is fastened to the angularly reciprocatingdrive member 156 so as to permit an initial angular relationship to beestablished between the arm 154 and the drive member 156 which, inturn,determines the longitudinal position of the connecting arm 146 and theangular position of the arms l42 prior to the beginning of one completeoscillation of the drive member 156.

It will be evident to those skilled in the art that the presentinvention may be subjected to many modifications and adaptations,without departing from the principle thereof. For example, although theinvention has been described as a modular unit which can be substitutedfor the standard modular powder compacting tooling in a powdercompacting press, it will be appreciated that the apparatus of thepresent invention may be built in any convenient form and operated byany convenient means well known in the art. As another example ofmodification of the invention, the upper plate member maybe separatelyoperated by appropriate independent means, resulting in dispensing withthe Belleville spring 92 (FIG. 1) and/or the coil springs 88. Also, oneof the pairs of feed pinch rolls 98-l00 or l02-104 may be omitted, andthey may be driven by any other convenient intermittent drive means suchas, for example, a star-wheel drive mechanism, or the like. The feedpinch rolls could also be replaced by intermittently driven sprocketwheel means or by oscillating claw means with or without appropriate pinregistration means, as is common in the motion picture industry foradvancing photographic film in registration with a picture taking orprojecting window, which will obviously require utilizing the stockmaterial in the form of a preperforated tape with appropriateperforations disposed along one edge of the tape, or both edges, as iscommon practice in the photographic art.

It will be appreciated that terms and expressions such asfvertical,horizontal, upper," lower, etc. are

relative terms used only for the purpose of orientation of the diverseelements relative to the drawing in order to facilitate the descriptionof the invention with reference to such drawing.

Although the apparatus of the invention has been described as capable offorming circularly annular arti- I cles, it will be appreciated that theprinciples of the invention are applicable to forming articles of anyrequired peripheral shape, such as oval, triangular, square, rectangularor irregular shaped articles provided with one, two or more apertures ofany peripheral shape whatsoever.

Having thus described the invention by way of a typical embodimentthereof, what is claimed as new is as follows:'

1. An apparatus for punching an annular part from a sheet of stockmaterial, said apparatus comprising a first plate member, an aperture insaid first plate member, a first punch disposed for reciprocationthrough said aperture, a longitudinal bore extending axially throughsaid first punch, a second plate member, an aperture in said secondplate member, a second punch disposed for reciprocation through saidsecond plate member, said second punch having a projecting end portionadapted to fit the longitudinal bore of said first punch, and means forreciprocating said first and second punches and one of said platemembers relative to the other in timed relationship for sequentiallyclamping said stock material between said plate members, reciprocatingsaid first punch in engagement with a surface of said stock material,reciprocating said second punch to project the end portion thereofwithin the longitudinal bore of said first punch for punching a slugfrom said stock material, retracting said second punch and reciprocatingsaid first punch to project through the aperture in said second platefor punching said annular part from said stock material.

2. The apparatus of claim 1 wherein said sheet of stock material is inthe form of a continuous ribbon or tape and further comprising means forsequentially advancing said ribbon or tape to a position presenting afresh portion of said stock material to the action of the punches forsequentially punching a plurality of said annular parts.

3. The apparatus ofclaim 1 further comprising means for extracting saidslug from said bore in said first punch.

4. The apparatus of claim 3 wherein said means is an aspirator means.

5. The apparatus of claim 1 further comprising means for extracting saidannular part form the aperture in said second plate.

6. The apparatus of claim 5 wherein said means comprises said firstpunch adapted to advance during retraction of said second punch to aposition ejecting said annular part from said aperture in said secondplate member.

7. The apparatus of claim 6 further comprising aspirator means forrecovering said annular part.

8. The apparatus of claim 2 further comprising a plurality of pairsofsaid first and second punches in at least one row disposedtransversely to the axis of advance of said ribbon or tape, and meansfor reciprocating said first and said second punches in unison in timedrelationship for simultaneously punching a plurality of said annularparts.

9. The apparatus of claim 8 further comprising single aspirator meansfor each cavity in said second plate for recovering said annular partsindividually and a single receptacle connected to each aspirator means.

10. The apparatus of claim 1 wherein said first plate member is disposedbelow and said second plate member is disposed above said sheet of stockmaterial.

11. The apparatus of claim 10 wherein said second plate member ismounted for reciprocation in unison with said second punch until thesecond plate member engages a surface of said stock material forclamping said stock material between said first and second platemembers, and biasing means are disposed for maintaining said secondplate member in engagement with said surface of the stock materialduring punching of said slug and of said annular part from saidmaterial.

12. The apparatus of claim 2 wherein said means for sequentiallyadvancing said ribbon or tape of stock material comprises a pair ofopposed pinch rolls, intermittent drive means for at least one of saidrolls for pulling said ribbon or tape axially between said plate memberswhen said plate members are reciprocated away from each other.

13. The apparatus of claim 12 wherein said roll driven by saidintermittent drive means is peripherally provided with a roughenedsurface for deformably engaging a surface of said ribbon or tape afterpassage between said plate members.

14. The apparatus of claim 12 wherein said intermittent drive meanscomprises a crank arm mounted for radial motion at an end about an axiscoincident with the axis of said roll, one-way drive meansinterconnecting said crank arm and said roll at said coincident axes,and means oscillating said crank arm through a predetermined arc.

15. The apparatus of claim 14 further comprising a second pair ofopposed pinch rolls, said first mentioned pair and said second pair ofpinch rolls being spatially disposed on opposite lateral sides of saidplate members, a second crank arm mounted for radial motion at an endabout an axis coincident with the axis of one of said rolls of saidsecond pair, one-way drive means interconnecting said crank arm and saidroll at said coincident axes, connecting arm means pivotallyinterconnecting said first and second crank arms for oscillation throughsaid predetermined arc in unison, and driving means for oscillating saidconnecting arm means.

1. An apparatus for punching an annular part from a sheet of stockmaterial, said apparatus comprising a first plate member, an aperture insaid first plate member, a first punch disposed for reciprocationthrough said aperture, a longitudinal bore extending axially throughsaid first punch, a second plate member, an aperture in said secondplate member, a second punch disposed for reciprocation through saidsecond plate member, said second punch having a projecting end portionadapted to fit the longitudinal bore of said first punch, and means forreciprocating said first and second punches and one of said platemembers relative to the other in timed relationship for sequentiallyclamping said stock material between said plate members, reciprocatingsaid first punch in engagement with a surface of said stock material,reciprocating said second punch to project the end portion thereofwithin the longitudinal bore of said first punch for punching a slugfrom said stock material, retracting said second punch and reciprocatingsaid first punch to project through the aperture in said second platefor punching said annular part from said stock material.
 2. Theapparatus of claim 1 wherein said sheet of stock material is in the formof a continuous ribbon or tape and further comprising means forsequentially advancing said ribbon or tape to a position presenting afresh portion of said stock material to the action of the punches forsequentially punching a plurality of said annular parts.
 3. Theapparatus of claim 1 further comprising means for extracting said slugfrom said bore in said first punch.
 4. The apparatus of claim 3 whereinsaid means is an aspirator means.
 5. The apparatus of claim 1 furthercomprising means for extracting said annular part form the aperture insaid second plate.
 6. The apparatus of claim 5 wherein said meanscomprises said first punch adapted to advance during retraction of saidsecond punch to a position ejecting said annular part from said aperturein said second plate member.
 7. The apparatus of claim 6 furthercomprising aspirator means for recovering said annular part.
 8. Theapparatus of claim 2 further comprising a plurality of pairs of saidfirst and second punches in at least one row disposed transversely tothe axis of advance of said ribbon or tape, and means for reciprocatingsaid first and said second punches in unison in timed relationship forsimultaneously punching a plurality of said annular parts.
 9. Theapparatus of claim 8 further comprising single aspirator means for eachcavity in said second plate for recovering said annular partsindividually and a single receptacle connected to each aspirator means.10. The apparatus of claim 1 wherein said first plate member is disposedbelow and said second plate member is disposed above said sheet of stockmaterial.
 11. The apparatus of claim 10 wherein said second plate memberis mounted for reciprocation in unison with said second punch until thesecond plate member engages a surface of said stock material forclamping said stock material between said first and second platemembers, and biasing means are disposed for maintaining said secondplate member in engagement with said surface of the stock materialduring punching of said slug and of said annular part froM saidmaterial.
 12. The apparatus of claim 2 wherein said means forsequentially advancing said ribbon or tape of stock material comprises apair of opposed pinch rolls, intermittent drive means for at least oneof said rolls for pulling said ribbon or tape axially between said platemembers when said plate members are reciprocated away from each other.13. The apparatus of claim 12 wherein said roll driven by saidintermittent drive means is peripherally provided with a roughenedsurface for deformably engaging a surface of said ribbon or tape afterpassage between said plate members.
 14. The apparatus of claim 12wherein said intermittent drive means comprises a crank arm mounted forradial motion at an end about an axis coincident with the axis of saidroll, one-way drive means interconnecting said crank arm and said rollat said coincident axes, and means oscillating said crank arm through apredetermined arc.
 15. The apparatus of claim 14 further comprising asecond pair of opposed pinch rolls, said first mentioned pair and saidsecond pair of pinch rolls being spatially disposed on opposite lateralsides of said plate members, a second crank arm mounted for radialmotion at an end about an axis coincident with the axis of one of saidrolls of said second pair, one-way drive means interconnecting saidcrank arm and said roll at said coincident axes, connecting arm meanspivotally interconnecting said first and second crank arms foroscillation through said predetermined arc in unison, and driving meansfor oscillating said connecting arm means.